Anti-Ro/SSA and/or anti-La/SSB antibodies are associated with adverse endometrial status.

PROBLEM: Anti-Ro/SSA and/or anti-La/SSB (anti-SSA/SSB) antibodies impair pregnancy outcomes, including embryo implantation and pregnancy maintenance. Optimal endometrial immune status is essential for successful pregnancy. However, whether these antibodies affect endometrial immune status is still unclear. Menstrual blood can be collected non-invasively, differs from peripheral blood, and can reflect the endometrial immune status. We herein focused on changes in subsets of natural killer (NK) cells and T cells in menstrual blood. METHODS OF STUDY: Menstrual blood samples from anti-SSA/SSB antibody-positive (n = 18) and anti-SSA/SSB antibody-negative control (n = 8) women were collected, and the profile of lymphocyte subsets was analyzed. The phenotypes of menstrual blood CD49a- and CD49a+ NK cells were compared, and the abundance of NK and CD49a+ NK cells in menstrual blood of the two groups was assessed. Additionally, CD4+T and CD8+T cells were investigated for their ability to secret functional cytokines. RESULTS: Menstrual blood contains a large number of (mostly CD49a+) NK cells, which exhibited a more exhausted phenotype with greater expression of the immune checkpoint molecules programmed cell death protein 1 and Tim-3 compared to CD49a- conventional NK cells. CD8+T cells in menstrual blood from anti-SSA/SSB antibody-positive women produced a stronger response after stimulation, accompanied by increased interferon-γ, tumor necrosis factor-α, and granzyme B secretion (P < 0.05, separately). CONCLUSION: Menstrual blood cell composition differs between anti-SSA/SSB antibody-positive women and normal controls, especially in terms of CD49a+ NK cells and CD8+T cells, unbalancing the immune cell composition and inflammatory uterine microenvironment and possibly contributing to adverse pregnancy outcomes.

The association between autoantibody types and salivary gland hypofunction in patients with primary Sjögren's syndrome.

BACKGROUND: This study analyzed the association between autoantibody types and salivary gland hypofunction in patients with primary Sjögren's syndrome (pSS). METHODS: A retrospective analysis was performed on patients who visited the Department of Orofacial Pain and Oral Medicine at Yonsei University Dental Hospital from January 1, 2010 to May 31, 2021, and who were diagnosed with pSS. Out of 191 patients who fulfilled the 2016 American College of Rheumatology/European League Against Rheumatism classification criteria, 50 were positive for both anti-Ro/SSA and anti-La/SSB, whereas 97 had anti-Ro/SSA but not anti-La/SSB antibodies. Forty-four patients for whom neither anti-Ro/SSA nor anti-La/SSB antibodies were found were diagnosed with Sjögren's syndrome by minor salivary gland biopsy. RESULTS: The anti-Ro/SSA antibody-positive group showed higher rheumatoid factor (RF) levels than the anti-Ro/SSA antibody-negative group. The anti-La/SSB antibody-positive group showed lower unstimulated whole saliva (UWS), stimulated whole saliva (SWS), higher erythrocyte sedimentation rate and RF level than the anti-La/SSB antibody-negative group. In addition, the group with both anti-Ro/SSA and anti-La/SSB antibodies showed lower UWS than the group with only anti-Ro/SSA antibodies. However, there were no significant differences in UWS or SWS after taking pilocarpine, and C-reactive protein. CONCLUSIONS: UWS and SWS were lower when a patient was positive for anti-La/SSB, showing that anti-La/SSB is more likely to be involved in salivary gland hypofunction than anti-Ro/SSA in patients with pSS. Therefore, performing laboratory tests, including anti-La/SSB, helps predict the prognosis of salivary gland function in patients with suspected pSS.

Hydroxychloroquine alleviates the neurotoxicity induced by anti-ribosomal P antibodies.

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by a wide spectrum of autoantibodies, among which anti-ribosomal P (anti-P) antibodies are considered to be closely related to the neuropsychiatric SLE (NPSLE). Hydroxychloroquine (HCQ) has been proven to be effective against a variety of autoimmune diseases and is an essential drug for the treatment of SLE. In this study, we investigated the effects of anti-ribosomal P (anti-P) antibodies on neural cells and determined whether hydroxychloroquine (HCQ) influenced the anti-P antibodies-induced changes. The results showed that the binding of anti-P antibodies with mouse neuroblastoma- 2a (N2a) cells and rat primary neurons resulted in elevated intracellular calcium levels, inducing decreased cell viability and cell apoptosis. These inhibitory effects were alleviated by HCQ in a concentration-dependent manner by reducing the intracellular calcium levels and modulating the expression of apoptotic proteins. In summary, our study demonstrates that anti-P antibodies induce neural cell damage. HCQ could ease the damage effects and may play a neuroprotective role in NPSLE.

[A case of dermatomyositis positive for anti-nuclear matrix protein 2 antibody without dermatologic symptoms].

We report a 47-year-old woman who presented with progressive myalgia, weakness in the proximal limbs, and dysphagia for a month and a half. No skin rash was observed on admission. Examination of MRI data suggested inflammatory changes in the proximal limbs and trunk muscles. Biopsy specimens from the left biceps muscle showed no perifascicular atrophy, but immunohistochemical staining revealed the presence of myxovirus resistance protein A (MxA) in myofibers, strongly suggesting dermatomyositis (DM). In addition, her serum was positive for anti-nuclear matrix protein 2 (anti-NXP-2) antibody, which is reportedly useful as a marker of DM without skin lesions. Her symptoms gradually improved upon intravenous methylprednisolone pulse therapy in conjunction with oral prednisolone, oral tacrolimus, and intravenous immunoglobulin therapy. Our findings suggest that in cases where inflammatory muscle disease is suspected, anti-NXP-2 antibody analyses should be considered for precise diagnosis, even if there are no dermatological symptoms.

The Emerging Role of Renal Tubular Epithelial Cells in the Immunological Pathophysiology of Lupus Nephritis.

Systemic lupus erythematosus (SLE) is a systemic, autoimmune disease that can involve virtually any organ of the body. Lupus nephritis (LN), the clinical manifestation of this disease in the kidney, is one of the most common and severe outcomes of SLE. Although a key pathological hallmark of LN is glomerular inflammation and damage, tubulointerstitial lesions have been recognized as an important component in the pathology of LN. Renal tubular epithelial cells are resident cells in the tubulointerstitium that have been shown to play crucial roles in various acute and chronic kidney diseases. In this context, recent progress has been made in examining the functional role of tubular epithelial cells in LN pathogenesis. This review summarizes recent advances in our understanding of renal tubular epithelial cells in LN, the potential role of tubular epithelial cells as biomarkers in the diagnosis, prognosis, and treatment of LN, and the future therapeutic potential of targeting the tubulointerstitium for the treatment of patients with LN.

Two of a kind? Immunological and clinical risk factors differ between recurrent implantation failure and recurrent miscarriage.

Recurrent miscarriage (RM) and recurrent implantation failure (RIF) are unsolved challenges in reproductive medicine. Whether RIF patients share the same risk factors as RM patients is a matter of debate. Besides clinical factors, immune alterations are discussed in both conditions. The scope of this study was to compare the prevalence of clinical and immunological risk factors in a large cohort of RM and RIF patients. Between 11/2011 and 02/2019, 613 RM and 185 RIF patients were included. A screening for anatomical malformations, endocrine, autoimmune, prothrombotic and parental chromosomal disorders was performed. The immune status was assessed using flow cytometry analysis of peripheral lymphocyte subpopulations and uterine natural killer cells (uNK cells) using immunohistochemistry. RM patients showed a higher rate of intrauterine adhesions and elevated antinuclear antibodies ≥ 1:160 (p < 0.05). A higher prevalence of submucous fibroids and increased factor VIII levels were observed in RIF patients (p < 0.05). The prevalence of an antiphospholipid syndrome (APLS) was low and did not differ between the two groups. RIF patients had higher numbers of peripheral regulatory T-cells (p < 0.05). Significant more RIF patients were diagnosed with elevated uNK cells (p < 0.05). Differences in clinical and immunological risk factors of RM and RIF patients reflect different entities. Lower Tregs in RM and higher uNK cells in RIF patients might be related to the previous exposure of the immune system to fetal cells. The low prevalence of an APLS indicates a potential overestimation of this factor in the pathophysiology of RM and RIF.

Injection of CD40 DNA vaccine ameliorates the autoimmune pathology of non-obese diabetic mice with Sjögren's syndrome.

BACKGROUND: Overexpression of CD40 has been reported in patients with primary Sjögren's syndrome (pSS). The increased CD40 expression promote autoimmune response and enhance inflammation in pSS. The aim of this study is to block CD40-CD154 interaction with CD40 DNA vaccine to slow the disease progression of SS in non-obese diabetic (NOD) mice. METHODS: Female NOD mice were treated with CD40 DNA vaccine, empty vector and normal saline. The salivary flow rate was measured, whereas lymphocytes infiltration in the salivary glands was assessed by histopathology. Expression of CD40 and B220 in salivary were examined by immunohistochemistry. Splenic lymphocyte phenotypes were analyzed by flow cytometry. CD40, IL-1ß, TNF-α and IL-6 levels in the salivary glands were detected by PCR. Serum anti-CD40 antibody was measured by ELISA. Serum anti-nuclear antibody (ANA) was monitored by immunofluorescence. RESULTS: NOD mice treated with CD40 DNA vaccine showed higher levels of anti-CD40 antibody compared with the controls. The expression of CD40 in the salivary glands of NOD mice in CD40 DNA vaccine group was decreased. The infiltration of lymphocytes was reduced in the salivary glands and saliva secretion was increased in the treatment group. The expression level of TNF-α and IL-6 in salivary glands were declined. The splenic dendritic cell and plasma cell populations were reduced and the level of ANA was decreased in NOD mice with CD40 DNA vaccine treatment. CONCLUSIONS: CD40 DNA vaccine inhibits the immune response and reduce inflammation in epithelial tissues SS in non-obese diabetic (NOD) mice, suggesting that CD40 DNA vaccine could be a new therapeutic approach in treatment of pSS.

Drug-induced Bullous Pemphigoid and Lupus Erythematosus Occurring under Anti-TNF-α and IL-6 Therapy in a Patient with Rheumatoid Arthritis.

A 65-year-old Japanese woman, who was diagnosed with rheumatoid arthritis and Sjögren's syndrome with various autoantibodies including anti-DNA antibody, developed bullous pemphigoid (BP) and hematological abnormalities like lupus erythematosus after adalimumab therapy. The discontinuation of adalimumab resolved those disorders but polyarthritis thereafter relapsed. The introduction of abatacept was not effective, but tocilizumab was found to be effective for polyarthritis, however, thereafter both bullous disease and severe pancytopenia developed. Discontinuation of tocilizumab was effective, but polyarthritis again developed, and baricitinib resolved it. There is an increasing number of reports of drug-induced BP and lupus erythematosus, and biologics might trigger an alteration in the pathophysiological/clinical course of rheumatic disorder.

Antinuclear antibodies in follicular fluid may reduce efficacy of in vitro fertilization and embryo transfer by invading endometrium and granular cells.

PROBLEM: The mechanism(s) by which antinuclear antibodies (ANA) induce implantation failure are not clear, and little information regarding the function of autoantibodies in reproductive tissues is available. METHODS OF STUDY: A total of 380 patients who underwent in vitro fertilization and embryo transfer (IVF-ET) were divided into control, serum positive, and follicular fluid (FF) positive groups based on the results of indirect immunofluorescence assay for ANA in the serum and FF. Immunofluorescence assay was performed to evaluate the existence of ANA in granular cells and endometrial tissues. Presence in FF of soluble apoptotic markers, including Bcl-2, Caspase-3, cleaved PARP, Cytochrome C, GAPDH, and p53, was assessed using magnetic bead based assays. RESULTS: The patients in the FF positive group had the lowest numbers of retrieved oocytes, fertilizations, and high-quality embryos. The fertilization rate, and the proportion of two pronuclear (2PN) embryos in patients in the FF positive group were significantly lower than those in the other two groups. The FF positive group also had the lowest clinical pregnancy rate, and the highest early miscarriage rate. Granulosa cells and endometrial tissues in patients in the FF positive group were ANA positive. High levels of BCL-2, Caspase-3, Cytochrome C, GAPDH, and p53 were found in the FF of patients in the FF positive group. CONCLUSIONS: Antinuclear antibodies in FF and endometrial tissues may cause imbalanced apoptosis, resulting in poor IVF-ET treatment outcomes. Local autoimmunity and cell apoptosis in reproductive tissues could be considered new therapeutic targets for improving IVF-ET treatment efficacy.

In vivo cutaneous antinuclear antibody positivity in palisaded neutrophilic and granulomatous dermatitis.

Palisaded neutrophilic and granulomatous dermatitis (PNGD) is commonly associated with underlying systemic inflammatory and neoplastic diseases, infections, and drug reactions. In vivo cutaneous antinuclear antibodies (ANA) have been described in skin biopsies from patients with known autoimmune disorders, but not previously reported in the setting of PNGD. We present two patients with systemic lupus erythematosus (SLE) and histopathologically confirmed PNGD. Direct immunofluorescence (DIF) studies revealed in vivo cutaneous ANA positivity in both patients. DIF findings in the skin mirrored serum autoantibody results. ANA positivity in skin specimens is reported as highly predictive of systemic connective tissue diseases (SCTD), although specific testing is not currently recommended as part of the laboratory work-up or diagnostic criteria for these disorders. In this case report, positive ANA results in skin biopsies of PNGD reflect the serological findings and clinical evidence of SLE in both patients. In vivo cutaneous ANA positivity is an interesting and supportive finding in PNGD in the setting of SCTD.

Dorsal cauda equina nerve root enhancement on magnetic resonance imaging due to ANNA-1-associated paraneoplastic polyneuropathy.

A 69-year-old female presented with subacute onset ascending weakness and paraesthesias. She was initially diagnosed with Guillain-Barré syndrome (GBS) based on her clinical presentation and cerebrospinal fluid (CSF) analysis showing albuminocytological dissociation. However, she was later found to have anti-neuronal nuclear antibody 1 (ANNA-1/anti-Hu)-positive CSF and was subsequently diagnosed with small-cell lung cancer. Her neurological symptoms were ultimately attributed to ANNA-1/anti-Hu-associated paraneoplastic polyneuropathy. During the course of her evaluation, she had magnetic resonance imaging findings of dorsal predominant cauda equina nerve root enhancement, which has not been previously described. The only previously reported case of cauda equina enhancement due to ANNA-1-associated polyneuropathy described ventral predominant findings. The distinction between ventral and dorsal enhancement is important, since it suggests that different patterns of nerve root involvement may be associated with this paraneoplastic syndrome. Therefore, ANNA-1-associated paraneoplastic inflammatory polyneuropathy can be considered in the differential diagnosis of cauda equina nerve root enhancement with ventral and/or dorsal predominance. This can potentially be helpful in differentiating ANNA-1 polyneuropathy from GBS, which classically has ventral predominant enhancement.

Toll-like receptor 7 agonist imiquimod prevents the progression of SLE in MRL/lpr mice via inhibiting the differentiation of T follicular helper cells.

Previous research has recently indicated that TLR7 is able to induce CD4+T cell anergy, which is the opposite of the role it plays in innate immune cells. Therefore, TLR7 ligands may be used as a manner in which to induce CD4+T cells "tolerance" in autoimmune diseases. T follicular helper (Tfh) cells were demonstrated to be a subset of CD4+T cells that help B cells produce antibodies. The abnormal activity of Tfh cells, though, is their function as a primary pathogenic factor in systemic lupus erythematosus (SLE). However, the role of TLR7 in Tfh cells is not clear. Our study was aimed at determining the influence of TLR7 on Tfh cells in a murine model of SLE (MRL/lpr mice). We were surprised to find that the frequency of Tfh cells and germinal center (GC) B cells was significantly reduced after treatment with the TLR7 agonist imiquimod. Imiquimod also significantly reduced the expression of inducible costimulatory molecule (ICOS) and programmed death 1(PD-1) in Tfh cells and decreased IL-21 secretion. Moreover, imiquimod significantly reduced the mRNA expression of several transcription factors, including Bcl-6, c-Maf, Batf3, Nfatc2 and Stat3, and enhanced the expression of Prdm1 and Stat5b in CD4+T cells. Imiquimod also ameliorated the progression of SLE in MRL/lpr mice by inhibiting anti-dsDNA antibodies and antinuclear antibody (ANA) secretion in the serum. Our findings indicated that TLR7 inhibited the development of Tfh cells both in vivo and ex vivo, which depended on many transcription factors aside from Bcl-6. Our results demonstrated that a TLR7 agonist has the potential to be used to inhibit Tfh cell responses during SLE.

Autoimmune markers for progression of Libby amphibole lamellar pleural thickening.

Exposure to Libby Asbestiform Amphibole (LAA) is associated with asbestos-related diseases, including mesothelioma, pulmonary carcinoma, pleural fibrosis, and systemic autoimmune diseases. The pleural fibrosis can manifest as a rapidly progressing lamellar pleural thickening (LPT), which causes thoracic pain, dyspnea, and worsening pulmonary function tests (PFT). It is refractory to treatment and frequently fatal.Objective: Because of the immune dysfunction that has been described in the LAA-exposed population and the association of pleural manifestations with the presence of autoantibodies, this study tested whether specific immunological factors were associated with progressive LPT and whether they could be used as markers of progressive disease.Methods: Subjects were placed into three study groups defined as (1) progressive LPT, (2) stable LPT, (3) no LPT. Serum samples were tested for antinuclear autoantibodies, mesothelial cell autoantibodies, anti-plasminogen antibodies, IL1 beta, and IL17; which have all been shown to be elevated in mice and/or humans exposed to LAA.Results: Group 1 had significantly higher mean values for all of the autoantibodies, but not IL1 or IL-17, compared to the control Group 3. All three autoantibody tests had high specificity but low sensitivity, but ROC area-under-the-curve values for all three antibodies were over 0.7, statistically higher than a test with no value. When all LPT subjects were combined (Progressive plus Stable), no marker had predictive value for disease.Conclusion: The data support the hypothesis that progressive LPT is associated with immunological findings that may serve as an initial screen for progressive LPT.

Glomerular Injury Is Exacerbated in Lupus-Prone MRL/lpr Mice Treated with a Protease-Activated Receptor 2 Antagonist.

Systemic lupus erythematosus (SLE) is characterized by the production of autoantibodies, which causes multi-organ injury such as lupus nephritis. SLE is associated with hypercoagulability. Activated coagulation factors such as tissue factor and VIIa complex and factor Xa activate protease-activated receptor 2 (PAR2). PAR2 promotes cytokine production through mitogen-activated protein kinase or nuclear factor kappa B signaling, and previous reports demonstrated that inhibition of PAR2 alleviated kidney injuries such as diabetic kidney disease and renal fibrosis in animal models. However, the involvement of PAR2 in the pathogenesis of SLE remains unclear. We therefore administered a selective PAR2 peptide antagonist, FSLLRY-NH2, to SLE-prone 4-month-old MRL-Faslpr mice for 4 weeks. Treatment with FSLLRY-NH2 caused the significant increases in the glomerular mesangial proliferation, glomerular deposition of both immunoglobulin G and complement factor C3d, and glomerular infiltration of Mac2-positive macrophages and CD3-positive T cells, compared with MRL-Faslpr mice treated with saline. In addition, the treatment with the PAR2 antagonist increased renal expression levels of tumor necrosis factor-α (Tnfa) and monocyte chemoattractant protein 1 (Mcp1) mRNA. Collectively, these results suggest that inhibition of PAR2 may increase the severity of inflammation in lupus nephritis; namely, opposite to previous observations, PAR2 has anti-inflammatory properties. We propose that activation of PAR2 could serve as a potential therapeutic option for patients with SLE.

Racial Differences in Cardiovascular Biomarkers in the General Population.

Background The incidence and clinical manifestations of cardiovascular disease (CVD) differ between blacks and whites. Biomarkers that reflect important pathophysiological pathways may provide a window to allow deeper understanding of racial differences in CVD. Methods and Results The study included 2635 white and black participants from the Dallas Heart Study who were free from existing CVD. Cross-sectional associations between race and 32 biomarkers were evaluated using multivariable linear regression adjusting for age, traditional CVD risk factors, imaging measures of body composition, renal function, insulin resistance, left ventricular mass, and socioeconomic factors. In fully adjusted models, black women had higher lipoprotein(a), leptin, d-dimer, osteoprotegerin, antinuclear antibody, homoarginine, suppression of tumorigenicity-2, and urinary microalbumin, and lower adiponectin, soluble receptor for advanced glycation end products and N-terminal pro-B-type natriuretic peptide versus white women. Black men had higher lipoprotein(a), leptin, d-dimer, high-sensitivity C-reactive protein, antinuclear antibody, symmetrical dimethylarginine, homoarginine, high-sensitivity cardiac troponin T, suppression of tumorigenicity-2, and lower adiponectin, soluble receptor for advanced glycation end products, and N-terminal pro-B-type natriuretic peptide versus white men. Adjustment for biomarkers that were associated with higher CVD risk, and that differed between blacks and whites, attenuated the risk for CVD events in black women (unadjusted hazard ratio 2.05, 95% CI 1.32, 3.17 and adjusted hazard ratio 1.15, 95% CI 0.69, 1.92) and black men (unadjusted hazard ratio 2.39, 95% CI 1.64, 3.46, and adjusted hazard ratio 1.21, 95% CI 0.76, 1.95). Conclusions Significant racial differences were seen in biomarkers reflecting lipids, adipokines, and biomarkers of endothelial function, inflammation, myocyte injury, and neurohormonal stress, which may contribute to racial differences in the development and complications of CVD.

Detecting mitotic cells in HEp-2 images as anomalies via one class classifier.

We propose a novel framework for classification of mitotic v/s non-mitotic cells in a Computer Aided Diagnosis (CAD) system for Anti-Nuclear Antibodies (ANA) detection. In the proposed work, due to unique characteristics (the rare occurrence) of the mitotic cells, their identification is posed as an anomaly detection approach. This will resolve the issue of data imbalance, which can arise in the traditional binary classification paradigm for mitotic v/s non-mitotic cell image classification. Here, the characteristics of only non-mitotic/interphase cells are captured using a well-defined feature representation to characterize the non-mitotic class distribution well, and the mitotic class is posed as an anomalous class. This framework requires training data only for the majority (non-mitotic) class, to build the classification model. The feature representation of the non-mitotic class includes morphology, texture, and Convolutional Neural Network (CNN) based feature representations, coupled with Bag-of-Words (BoW) and Spatial Pyramid Pooling (SPP) based summarization techniques. For classification, in this work, we employ the One-Class Support Vector Machines (OC-SVM). The proposed classification framework is validated on a publicly available dataset, and across various experiments, we demonstrate comparable or better performance over binary classification, attaining 0.99 (max.) F-Score in one case. The proposed framework proves to be an effective way to solve the mentioned problem statement, where there are less number of samples in one of the classes.

Dendritic cell-associated B7-H3 suppresses the production of autoantibodies and renal inflammation in a mouse model of systemic lupus erythematosus.

B7-H3 immune modulatory molecule has been implicated in the generation and pathogenesis of autoimmune diseases, the mechanism of action is less known. We explored the role of B7-H3 in the induction of autoantibodies and organ-directed inflammation in a murine systemic lupus erythematosus (SLE) model in which the immunization with DNA extracted from activated T cells induced the production of anti-DNA autoantibodies and subsequent glomerulonephritis, two hallmarks of human SLE. Mice deficient of B7-H3 or treated with a B7-H3 specific antibody produced significantly higher levels of anti-DNA autoantibodies and more severe glomerulonephritis than wild-type mice, indicating an inhibitory function of B7-H3 in this model. Interestingly, immunization of mice with DNA-pulsed dendritic cells induced severe SLE symptoms while B7-H3 on dendritic cells is required in this process. Importantly, treatment of mice with recombinant B7-H3Ig fusion protein effectively ameliorated progression of murine SLE, accompanied with decreased level of anti-DNA autoantibodies and alleviated glomerulonephritis, decreased autoantibody deposition and complement deposition in kidney. Our findings implicate a potential role of B7-H3 on dendritic cells in the induction of SLE and as a potential target for the treatment of autoimmune diseases.

Siglec-1 Macrophages and the Contribution of IFN to the Development of Autoimmune Congenital Heart Block.

Given that diseases associated with anti-SSA/Ro autoantibodies, such as systemic lupus erythematosus and Sjögren syndrome, are linked with an upregulation of IFN and type I IFN-stimulated genes, including sialic acid-binding Ig-like lectin 1 (Siglec-1), a receptor on monocytes/macrophages, recent attention has focused on a potential role for IFN and IFN-stimulated genes in the pathogenesis of congenital heart block (CHB). Accordingly, three approaches were leveraged to address the association of IFN, IFN-stimulated genes, and the phenotype of macrophages in affected fetal cardiac tissue: 1) cultured healthy human macrophages transfected with hY3, an anti-SSA/Ro-associated ssRNA, 2) RNA isolated from freshly sorted human leukocytes/macrophages after Langendorff perfusion of three fetal hearts dying with CHB and three healthy gestational age-matched hearts, and 3) autopsy tissue from three additional human CHB hearts and one healthy heart. TLR ligation of macrophages with hY3 led to the upregulation of a panel of IFN transcripts, including SIGLEC1, a result corroborated using quantitative PCR. Using independent and agnostic bioinformatics approaches, CD45+CD11c+ and CD45+CD11c- human leukocytes flow sorted from the CHB hearts highly expressed type I IFN response genes inclusive of SIGLEC1. Furthermore, Siglec-1 expression was identified in the septal region of several affected fetal hearts. These data now provide a link between IFN, IFN-stimulated genes, and the inflammatory and possibly fibrosing components of CHB, positioning Siglec-1-positive macrophages as integral to the process.

Cytosolic Internalization of Anti-DNA Antibodies by Human Monocytes Induces Production of Pro-inflammatory Cytokines Independently of the Tripartite Motif-Containing 21 (TRIM21)-Mediated Pathway.

Anti-DNA autoantibodies are a hallmark of systemic lupus erythematosus (SLE). A subset of anti-DNA IgG autoantibodies is cell-internalizable; thus they can enter living cells in the form of free IgG. However, the contribution made by the Fc region of internalized free-form IgG to the cytokine response has not been studied, despite the recent discovery of tripartite motif-containing 21 (TRIM21), a cytosolic Fc receptor involved in immune signaling. This study used an internalizable IgG anti-DNA antibody (3D8) to examine the cytokine responses of human monocytes to the Fc region of cytosolic free IgG. Internalization of 3D8 IgG and a 3D8 single-chain variable fragment-Fc (scFv-Fc) induced production of IL-8 and TNF-α via activation of NF-κB. By contrast, a 3D8 scFv (comprising variable domains alone) did not. This suggests Fc-dependent cytokine signaling. A 3D8 IgG-N434D mutant that is not recognized by TRIM21 induced greater production of cytokines than 3D8 IgG. Moreover the amounts of cytokines induced by 3D8 IgG in TRIM21-knockdown THP-1 cells were higher than those in control cells, indicating that cytokine signaling is not mediated by TRIM21. The results suggest the existence of a novel Fc-dependent signaling pathway that is activated upon internalization of IgG antibodies by human monocytes.

Uncommon patterns of antinuclear antibodies recognizing mitotic spindle apparatus antigens and clinical associations.

Antinuclear antibodies (ANA) are key biomarkers in the evaluation of rheumatic diseases. The prevalence and clinical significance of uncommon or rare patterns, particularly those directed at the mitotic spindle apparatus (MSA), are not well understood. We aimed to investigate the prevalence and clinical significance of anti-MSA patterns in a Colombian population.During 2013 and 2014, 113,491 consecutive determinations of ANA were studied for the presence of uncommon patterns. Clinical and laboratory data of anti-MSA positive patients were retrospectively collected and analyzed.Of the 113,491 patients tested, 60,501 (53%) were positive for ANA, of which 834 (1.3%) were positive for uncommon/rare patterns of ANA (anti-MSA in 592 cases). Of these 592 cases, complete data were available in 329 patients, of whom 116 had an established diagnosis. Anti-MSA antibodies were the only ANA positive test in 81% patients. At least one fine reactivity was identified in 19/116 (16.3%) of ANA-positive patients, of which anti-Ro was the most prevalent (18/116, 15.5%).The most frequent patterns were nuclear mitotic apparatus (NuMA) (56%) and MSA-2 (25%). The NuMA pattern had the highest ANA titers: mean 320 (range 80-2560) and behaved as monospecific antibodies. The most frequent systemic autoimmune diseases were Sjögren syndrome (SS) (18.1%), rheumatoid arthritis (RA) (13.8%), and systemic lupus erythematosus (SLE) (11%). Undifferentiated connective tissue disease (UCTD) was associated with the centrosome (P < .001), NuMA (P < .02) and MSA-2 (P < .45) patterns. Chronic idiopathic urticaria (CIU) was associated with the NuMA pattern (P < .02) and sensorineural hearing loss (SNHL) was associated with the MSA-2 (P < .001), centrosome (P < .68) and CENP-F (P < .38) patterns, previously unreported findings. Malignancies were found in 8 patients (50% were papillary thyroid cancer).In a large cohort of ANA determinations, uncommon patterns were found in around 1% of cases. The most frequent anti-MSA patterns found were NuMA and MSA-2. More than 50% of patients with anti-MSA had an associated CTD, mainly SS, RA and SLE, and anti-MSA behaved as monospecific antibodies. Other entities of presumed autoimmune origin, like CIU and SNHL, might be associated with these patterns.